Question
What will be the energy of a photon which corresponds to the wavelength of $$0.50\,\mathop {\text{A}}\limits^{\text{o}} ?$$
A.
$$3.98 \times {10^{ - 15}}J$$
B.
$$3 \times {10^{15}}J$$
C.
$$3.9 \times {10^8}J$$
D.
$$3 \times {10^{ - 34}}J$$
Answer :
$$3.98 \times {10^{ - 15}}J$$
Solution :
$$\eqalign{
& E = h\upsilon = \frac{{hc}}{\lambda } \cr
& = \frac{{\left( {6.626 \times {{10}^{ - 34}}J\,\,s} \right)\left( {3 \times {{10}^8}m\,\,{s^{ - 1}}} \right)}}{{0.5 \times {{10}^{ - 10}}m}} \cr
& = 3.98 \times {10^{ - 15}}J \cr} $$